STEEL SPECIAL INSPECTIONS AND THE STEEL WARRIORS WHO PERFORM THEM
The subject of this article is steel special inspections, and the central theme is the hundreds of different items that steel special inspectors are responsible for during all of the various phases of steel construction. Not only are there a “gazillion” different types of inspection tasks required by the steel codes, but dozens of steel building codes and standards also stipulate acceptance criteria to measure the quality of steel construction. No other discipline of building construction invokes as many separate building codes and standards as steel construction does.
If the type of construction is steel decking, the inspector must apply the Steel Deck Institute (SDI) criteria. If the construction is cold-formed steel, the inspector must use the American Iron & Steel Institute (AISI) S240 code criteria. If the construction type is structural steel, then the inspector must perform the inspection duties per the American Institute of Steel Construction (AISC) and AISC 360, “Specification for Structural Steel Buildings,” as well as the Research Council on Structural Connections (RCSC) for bolted connections. If it is the fabrication or erection of structural steel, then AISC 303, “Code of Standard Practice,” acceptance criteria must be applied. If the inspection involves welding, then the special inspector must apply various American Welding Society (AWS) codes such as AWS D1.1 (Structural Welding Code), AWS D1.3 (Sheet Steel Welding Code), or AWS D1.4 (Reinforcing Steel Welding Code).
In addition to the aforementioned steel codes, the steel special inspector must acknowledge the International Building Code (IBC) acceptance criteria since the IBC code is the KING of model codes and adopted throughout the United States. The steel special inspector must also be familiar with the particular statewide code requirements of the specific jurisdiction in which the project is located. These are just some reasons we’re calling steel special inspectors STEEL WARRIORS.
The steel special inspector is responsible for observing code compliance on numerous construction procedures and construction materials during the erection phase of a structural steel frame high-rise building with welded elements. Initially, the inspector must ascertain if the project welders are qualified (certified) to perform the welding required. How does the special inspector know if the welders are qualified? Each welder must present a satisfactory Welder Performance Qualification (WPQ) before welding on the project. The WPQ is issued after one or several tests administered in accordance with AWS code requirements.
Regarding the welders, administering and verifying the proper weld certification and completing the appropriate (and correct) paperwork is not for the faint-hearted. To what welding code are you certified? For what type of material are you certified? In what positions are you certified to weld that material? What thickness are you certified to weld with what process, position, and material type? Plate or pipe? What electrode? Is it 6010, 7018, or something else?
No wonder the steel special inspections umbrella creates confusion sometimes! In addition to these responsibilities, the special inspector must perform the following (among other things):
To pay tribute to the steel warriors out there across the country, we would like to present some narrative about their everyday work lives in the form of some war stories.
War Story #1 – Salt Lake City, Utah
A convention center-type exhibit hall was being constructed south of Salt Lake City. The structure had a wide-open floor space with no support columns. It required long-span trusses and heavy columns to support them, both for the space’s dimensions and the possible snow loads on the roof. The fabricator was in Tennessee due to the truss lengths involved!
When materials arrived, Brett Clarke, AWS CWI, and the general contractor’s QC inspector noted visual irregularities in complete joint penetration (CJP) welds in the columns. Attempts to gain shop inspection records for this project were unsuccessful, so the Engineer-of-Record was petitioned to change the fieldwork scope and add ultrasonic testing (UT) to the questionable shop-welded CJP connections. After UT testing and 51 welds later, one weld finally passed the acceptance criteria in AWS D1.1. The six UT inspectors were very busy people.
The end result? There were 660 CJP welds repaired, requiring 29 days and 31 erector personnel. Mr. Clarke had informed the erector foreman that some of the welds looked ultrasonically like there could be a void of a pencil-sized diameter in the welds; he scoffed and said no way. He returned to Brett later, telling him he was wrong – some of the voids found were the diameter of his thumb!
So now we have AISC 360, “Specification for Structural Steel Buildings,” which mandates minimums for inspection before, during, and after welding, now helping to prevent errors in fabrication. It is thought in the case of the story above that the second shift just came to work, turned the part over, and started welding from the second side without proper weld preparation. Was public safety restored and human lives saved in the early 2000s because two inspectors thought something didn’t look right? Possibly! They may be heroes, not just steel warriors!?
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War Story #2 – New York City
F&R’s Brian Pratt, AWS CWI, was contacted to perform an audit of a large structural steel fabrication facility that was providing structural steel components for a project in New York City. The project had full-penetration welds completed at the fabrication shop. The shop had current AISC Certified Fabricator status, meaning that, according to IBC Chapter 17 requirements, they could perform shop-level special inspections of the steel they fabricated without further inspections required by a third party (IBC Section 1704.2.5.1). F&R was requested to perform the shop audit because the project specifications required a third party to visit the facility, essentially providing a one-day audit of the facility’s quality control program.
Chapter N of AISC 360, referenced in Chapter 35 of the IBC code, lays out the non-destructive testing (NDT) requirements for full-penetration welds. The subject project was a Risk Category III project, and Chapter N specifies that 100% of all full-penetration welds require ultrasonic testing (UT) for Risk Category III structures. Knowing the code required UT testing of the full-penetration shop welds, F&R requested copies of the NDT technician qualification documentation and shop UT reports; however, the fabricator did not have a certified NDT technician employed at this facility, and no UT was performed. The fabricator pointed out that the AISC 303 Code of Standard Practice states that any NDT requirements for the project must be included in the project specifications provided for bidding. The fabricator’s project review process included a review of the project specifications for NDT requirements, as required by the Code of Standard Practice. There were no requirements for UT listed in the project specifications. Therefore, the fabricator did not perform any shop UT. At a significant cost and time delay, a third party NDT technician was hired to perform UT on the remaining shop-fabricated parts and perform UT in the field for the parts already delivered to the project site.
Specification writers need to fully understand the AISC 303 Code of Standard Practice and ensure that all AISC 303 NDT requirements for the project are included in the specifications. It is just as important that fabricators realize that the IBC code and AISC 360 take precedence over AISC 303. As indicated above, an AISC Certified Fabricator, with the additional qualification as a New York City Approved Fabricator, did not make the connection that their work must meet the AISC 360 Chapter N NDT requirements for UT of full penetration welds because it was not explicitly listed in the project specifications.
Based on the size of the fabricator and the scope of projects fabricated at this facility, there is a strong chance that other projects were fabricated without performing the code- required NDT. Unfortunately, F&R has uncovered similar instances of other fabricators not fully understanding the NDT requirements for their project and, like the reference project, failing to perform the NDT because it wasn’t listed in the project specifications.
The primary takeaway or lesson learned, in this case, is that the structural engineer and the special inspector should always review the inspection reports from the steel fabricator to verify that all the shop inspections, including NDT, were performed in accordance with both the project specifications and the requirements of the IBC code and AISC 360. This includes fabricators with AISC Certified Fabricator status.
War Story #3 – Central Virginia
The project was a nine-story residential dormitory-type building utilizing pre-fabricated cold-formed metal framing (CFMF) wall panels. Each floor deck was constructed with cast-in-place concrete. The contract documents and the project statement of special inspections adopted the 2018 version of the IBC code, which adopts AISI S240-15, “North American Standard for Cold-Formed Steel Structural Framing,” building code. The S240-15 code was created in 2015 and never existed before the adoption of the code by IBC 2018. S240 merged and superseded previous AISI codes S200, S210, S211, S212, S213, and S214. AISI S240 also created a new Chapter D, “Quality Control and Quality Assurance,” which lists a host of inspections that must be performed during the construction phases of a project. Since S240 was a brand new cold-formed steel code, there was (and is) a lot of confusion about the standard and the project code-required inspections.
To add to the confusion, the pre-fabricated CFMF panels were constructed outside of Virginia in a state that did not adopt the new S240 cold-formed steel framing code. The out-of-state fabricator felt they did not have to construct the CFMF panels per the S240 code since their state did not adopt the new S240 code. Actually, the fabricator (wherever they are located) must construct the CFMF panels in accordance with the applicable codes adopted by the jurisdiction where the project is located. In this case, this was Virginia. Numerous discrepancies were observed by the metals inspectors in both field construction procedures and fabrication plant procedures due to the lack of knowledge of design professionals, building officials, fabrication plant personnel, and job site staff. In this instance, the fabricator agreed to provide a QC inspector (at the job site) who noted and corrected a number of discrepancies on the project prior to the owner’s QA conducting inspections. S240, Chapter D, allows the combined use of the QC and QA inspections under certain conditions, thereby saving the client many inspection costs. When all the project team members got on the same page, the project went much smoother and according to code. Thankfully, the steel warriors were familiar with the new S240 cold-formed framing code, which helped get the project back on track and kept it on track until it was completed.
Speaking in Code thanks Brett Clarke, AWS CWI, and Brian Pratt, AWS CWI, for their collaborative efforts in developing this war story article about steel inspections. Brett is the Technical Chief of NDT and Brian serves as Director of Metals and NDT with the F&R Metals Department. Although both are based in the F&R Roanoke, VA, office, their work takes them throughout the Mid-Atlantic F&R footprint and beyond.
But wait! We have a lot more to say!
For a complete picture of the Code and how it relates to Special Inspections, F&R would love to provide a virtual AIA-accredited Lunch & Learn presentation to the professionals at your firm.
Trouble Deciphering the Code? Call the Experts at F&R! Alan S. Tuck, Director of Code Compliance & Training | T 540.344.7939 | M 540.798.4440 | [email protected]